Refrigeration



A ril 20, 1943. E. s. LYNGER 2,317,233

' REFRIGERATION Filed June 22, 1938 5 Sheets-Sheet l' 2a F? ,OR

QQH W ATTORNEY.

April 20, 1943.

E. s. LYNGER 2,317,283

REFRIGERATION Filed June 22, 1938 5 Sheets-Sheet 2 IN VENTOR.

p 1943- E. s. LYNGER 2,317,283

REFRIGERATION Filed Juhe 22, 1938 5 Sheets-Sheet 3 E. s. LYNGER2,317,283

REFRIGERATION April 20, 1943.

Filed June 22, 1938 5 Sheets-Sheet 5 W INVENIT R. BY w L4 ATTORNEY.

Patented Apr. 20,

w I SigfridLY I a by memo asslgnm f: York, N. Y.,

Stockholm, Swedem'assignor, cuts, to Serve], Inc., Now a corporation ofDelaware rmany July 6, .1937

. 'nppllcationlune 22,-1938, Serial No. 215411 p mac 7 I Claims.

This invention relates to refrigeration, and it is an object oftheinvention to provide an improvement for transferring heat wherebycooling may be effected at one or a plurality of places at a higherlevel than a .source ofrefrigeration.

The above and other objects and advantages of the invention will'becomeap arent from the following description taken in conjunction with theaccompanying drawings forming a part of this specification, and ofwhich: I

Fig. 1is a view more or less diagrammatically illustrating arefrigeration system together with a heat transfer system embodying theinvention;

Fig. 2 is an enlarged view, partly in section, illustrating more clearlythe heat transfer system shown in Fig. 1;

Fig. 3 is a fragmentary view diagrammatically illustrating amodification of the invention shown in Figs. 1 and 2 y Fig. 4 is a viewmore or less diagrammatically illustrating another modification of theinvention.

,Fig. 5 is a view diagrammatically illustrating a. further modificationof the invention and in which a plurality of places of cooling areprovided from the surroundings,

- through a conduit 20, thereby producing a refrigerating effect withconsequent absorption of heat The rich gas mixture of refrigerant vaporand inert gas formed in at a higher level than a source ofrefrigeration;

and

Fig. 6 is a fragmentary view illustrating a still further modificationof the invention having a plurality of places of cooling at a higherlevel than a source of refrigeration.

In Fig.1 the invention is shown in connection with a. refrigerationsystem of a uniform pressure absorption type. Such a system includes agenerator l0, condenser H, evaporator or-cooling element 12, and anabsorber l3 which are interconnected in a manner well-known in the art,and which will briefly be described hereinafter. The system contains asolution of refrigerant in absorption liquid, such as ammonia in water,for example, and also an inert gas or auxiliary agent, such as hydrogen.

The generator I9 is heated in any suitable manner, as by a gas. burnerH, for example, which projects its flame into lower end of a flue l5.Due to heating by burner 14 refrigerant vapor is expelled from solutionin generator Ill. The refrigerant vapor flows upwardly through a conduitl6 into the air-cooled condenser H where the vapor is condensed andflows through conduit l1 into evaporator l2. 7, I

The evaporator I2 is located fife. space or compartment l8 formed bythermally insulated walls evaporator I2 flows therefrom through aconduit 2t, one passage of a gas heatexchanger 22, and conduit 23 intothe lower part of absorber 13..

The absorber I3 is diagrammatically shown in the form of a looped coilhaving a plurality of cooling fins 24 secured thereto forfair cooling.In absorber l3 the rich gas mixture flows counter-current to downwardlyflowing weak absorption liquid which enters through a conduit 25. Theabsorption liquid absorbs refrigerantvapor from the inert gas, and inertgas weak in refrigerant vapor flows from absorber l3 through a conduit26, a second passage of gas heat exchanger 22, and conduit 20 into theupper part of evaporator l2.

Absorption liquid enriched in refrigerant flows from the lower part ofabsorber I3 into an accumulation vessel 21. From vessel 21 enrichedliquid flows through an inner conduit 28 of a liquid heat exchanger 29to a coil 30 which is disposed about the lower end of flue l5. Due toheating by burner ll, liquid is raised by vaporlift action from coil 30through conduit 3| into the upper-part of generator Ill. The refrigerantvapor expelled out of. solution in generator ID, together withrefrigerant'vapor entering through conduit 3|, flows upwardly throughconduit into condenser I I, 'as explained above.

The absorption liquid from which refrigerant has been expelled flowsfrom generator l0 through conduit 32, outer conduit 33 of liquid v heatexchanger 29, and conduit 25 into the upper part of absorber l3.

The lower end oi condenser H is connected by a conduit 3| to the gascircuit, as at gas heat exchanger 22, for example. By providing conduit34 anynon-condensible gas which passes through the condenser will flowto the gas circuit and not be trapped in the condenser.

The refrigerating effect produced by evaporator or cooling element l2 ofthe refrigeration system is utilized to cool and liquify a volatilefluid flowing through a coil 35 which extends longitudinally within thecooling element, as shown in Fig. 2. The coil 35 constitutes thecondenser of a heat transfer system embodying the invention wherebycooling may be effected at a place above the cooling element I2.

The heat transfer system includes an evaporator 36 which is of theflooded type and located at a higher level than condenser 35. Theevaporator 36 is disposed in a thermally insulated space 31 and includesa receiver 33 having a looped coil 33 connected thereto.

The condenser 35 and evaporator 36 form part of a closed fluid circuitwhich is partly filled with a suitable volatile liquid. The volatileliquid evaporates in evaporator 36 and takes up heat thereby producingcold. The vapor flows from evaporator 36 through a conduit 43 intocondenser 35 in which the vapor is cooled and condensed by coolingelement l2.

In accordance with the invention, structure including an accumulationvessel 4| is provided for raising liquid from condenser 35 to evaporator36 so that cooling may be effected in space 31. To the lower end ofcondenser 35 is connected a U-shaped conduit 42 which extends belowvessel 4| and is connected to the-bottom thereof.

To vessel 4| is connected an overflow conduit 43 having an invertedU-shaped bend 44. In Fig. 2 the upper closed end of bend 44 is atsubstantially the same level as the upper part of vessel 4|. From bend44 conduit 43 extends downwardly and is connected to an intermediatepart of a vaporizer 45. The vaporizer 45 constitutes a heat receivingpart and is shown in heat exchange relation with the upper part ofgenerator l3. Above the connection of conduit 43 the vaporizer 45 isconnected by another conduit 46 to the upper part of vessel 4|.

' The operation of the heat transfer system just described issubstantially as follows: Assuming that evaporator 36 is filled withliquid, vapor is formed therein and flows through conduit 43 intocondenser 35 in which the vapor is cooled and condensed, as explainedabove. The con densed fluid flows through U-shaped conduit 42 intoaccumulation vessel 4|. With continued evaporation of liquid inevaporator 36 and condensation of vapor in condenser 35, the liquidlevel will rise in vessel 4|.

When the liquid level in vessel 4| rises sulficlently, liquid issiphoned by inverted U-shaped bend 44 in conduit 43 and the siphonedliquid flows into vaporizer 45. This may occur when a definite quantityof liquid has evaporated in evaporator 36, such as, for example, half ofthe liquid in the evaporator.

The liquid overflowing into vaporizer 45 is vaporized and the vaporformed therein flows through conduit 46 into the upper part of vessel4|. The vapor pressure continues to increase in vaporizer 45, conduit46, and in the space above the liquid surface in vessel 4| This vaporpressure increases to a value higher than the vapor pressure aboveliquid in evaporator 36. When the vapor pressure above the liquidsurface in vessel 4| builds up sufliciently, liquid is forced upwardthrough conduit 42, condenser 35, and conduit 43 into receiver 33.

The heat transfer system is so constructed and arranged that sufficientliquid is siphoned from vessel 4| into vaporizer 45 before the liquidlevel is depressed in vessel 4| below the connection of conduit 43thereto. The quantity of liquid siphoned into vaporizer 45 is suiflcientwhen the vapor pressure can build up to a value to produce the necessaryforce to lift liquid from vessel 4| into receiver 38.

When the vapor in vessel 4| reaches the lower end of the right-hand legof U-shaped conduit of conduit 42, condenser 35. and conduit 43 willflow back into vessel 4| The trapped vapor released into the left-handleg of U-shaped conduit 42 is condensed in condenser 35 while theremaining vapor in vessel 4| is condensed therein. It will be apparentthat vapor is formed in v porizer 45 when the liquid rises suiflcientlyin vessel 4|, and that this rise of liquid is recurring and constitutesa recurring condition taking place within the heat transfer system tocause intermittent flow of liquid from vessel 4| to condenser 35.Further, the heat transfer system is self-- actuating and operates inaccordance with a condition taking place solely within the systemandindependently of changes in an operating condition of the refrigeratingapparatus or changes in temperature or pressure occurring outside of orexternal to the heat transfer system.

The periods during which liquid is raised in the system alternate withperiods during which vapor is formed in evaporator 36 and condenses incondenser 35. The periods of liquid raising are relatively shortcompared with the periods of liquid evaporation, whereby space 31 iskept a a low temperature practically all of the time By locatingaccumulation vessel in space II which is at a low temperature,vaporization of liquid in this vessel is prevented.

At the termination of the periods when liquid is raised to a higherlevel into receiver 33, the

pressure in the heat transfer system becomes equalized. Since the lengthof time of the liquid lifting periods is relatively short, very littleheat of condensation is transferred to liquid in vessel 4| by the smallamount of vapor condensing therein.

In Fig. 3 is diagrammatically shown a modification of the lower part ofthe heat transfer system of Figs. 1 and 2. As in Fig. 2, themodification of Fig. 3 shows vessel 4| connected to a U-shaped conduit42 which is connected at its upper end to condenser 35. The upper partof vessel 4| is connected by conduit 46 to the upper part of vaporizer45 which is in thermal contact with the upper part of generator l3.

In-place of the overflow conduit 43 having an inverted U-shaped bend 44,liquid overflows from vessel 4| in Fig. 3 over the upper peripheral edge41 of a shallow funnel 43 which is located in any 42 during a liquidlifting period, trapped vapor suitable manner within the upper part ofthe vessel. The bottom of funnel 48 is connected by a conduit 43 to anintermediate part of vaporizer 45 below the connection of conduit 46.

The operation of the heat transfer system including the modification ofFig. 3 is substantially the sameas that of Fig. 2 and described above.As the liquid level rises in vessel 4| in Fig.- 3, liquid overflows overthe upper edge 41 of funnel 43 and flows through conduit 43 intovaporizer 45. The vapor formed in vaporizer 45 flows through conduit 46into the upper part of vessel 4 I. When the vapor pressure in the upperpart of vessel 4| builds up sufficiently, liquid is forced downwardlytherein and through conduit 42 into evaporator 36 at the upper level.

The funnel 43 is so dimensioned that when the liquid level in vessel 4|rises to cause overflow of liquid, the overflow is relatively largewhereby sufllcient liquid flows into vaporizer 45 before the liquidlevel in vessel 4| falls below the upper edge 41 of funnel 43. Theamount of liquid flowing into vaporizer 45 is sufllcient, as pointed outabove in connection with Fig. 2, so that the vapor pressure will buildup to a value suflicient to force liquid from vessel 4| into receiver33.

and 3. The

amazes In Fig. 4 is more or less diagrammatically lllustrated anothermodification of the heat transfer. systems described above and shown inFigs. 2 parts of the primary refrigeration system similar to those shownin Figs. 1 and 2 are designated by the same reference numerals. Theevaporator 36a including receiver 38a and looped coil 39a is at a higherlevel than condenser 35a which is in thermal exchange relation withcooling element l2. As in the other embodiments previously described,the volatile liquid evaporates in evaporator 36a. and takes up heatthereby producing cold. The vapor flows from evaporator 36a throughconduit 40a. into condenser 35a in which the vapor is cooled andcondensed by cooling element l2.

Inaccordance with this modification, liquid is raised into receiver 38abystructure including an accumulation vessel Ma which is more or less inthe shape of a vertical cylinder. The lower end of condenser 35a isconnected bya U-shaped conduit 42a to the lower part of vessel 4|a.Within vessel 4|a. is disposed a vertical conduit 50 having a coil 5 atthe lower end thereof. The lower end of coil 5| is connected by a liquidtrap 53 and conduit-52 to anintermediate part of vaporizer 45a. Thevaporizer 450, at a point above the connection of conduit 52 isconnected by a conduit 54 to the upper end of vertical coriduit 5o.

From the upper part of vessel Ila a'conduit 55 extends downward and isconnected at its lower end to the left-hand leg of liquid trap 53. Thelower end of conduit 55 is in communication with the lower end of aconduit 56 which is also connected to the left-hand leg of trap 53 belowthe connection of conduit 55. The upper end of conduit 56 is connectedat51 to the lower end of conduit 40a and above condenser 35a. The conduits42a and.56 are connected by a short oblique conduit 58 I The operationof the modificationof Fig. 4 generally is the same as described above inconnection with the other embodiments and differs in the'manner in whichliquid israised into receiver 38a. -With evaporation of liquid inevaporator 36a and condensation of the vapors in condenser 35a, theliquid level rises in accumulation vessel Ma. .When the liquid levelrises sufiiciently in vessel 4|a, liquid overflows from the left-handleg of U-shaped conduit 42a through oblique conduit 56 and into conduit56. The liquid overflowing into conduit 56 is conducted through liquidtrap vaporizer 45a.

The liquid entering vaporizer 45a is vaporized therein and the vaporflows through conduit 54 into vertical conduit 50 and coil 5|. Sinceduit 50 and coil are surrounded by liquid which is. at a considerablylower temperature than vaporizer 45a, condensation of vapor takes placein these parts. The condensate flows from coil 5| through liquid trap 53and conduit 52 back to vaporizer 45a where The vaporizer 45a, conduits54 and 50, coil 5|, liquid trap Bland conduit 52 constitute a localvaporizationecondensation circuitin which liquid is vaporized invaporizer 45a and the vapors are condensed in conduit 50 and coil 5|.Liquid vaporizing in vaporizer 45a takes up heat from generator l0, and50 and coil 5| gives up heat to liquid in vessel Ma.

Whena liquid lifting period is started with overflow of liquid throughoblique conduit 58, the vaporization-condensation circuit -justdescribed 53 and conduit 52 into it is again vaporlzed.

the vapors condensing in conduit I of coil 5| is immersed in upwardlythrough the assures suflicient liquid flowing into vaporizer a to effectheating of liquid in vessel Ma. With heating of liquid in vessel a,evaporation of liquid takes place in this vessel whereby the vaporpressure above the liquid surface builds up, thereby forcing liquiddownwardly in vessel Haand left-hand leg of U -shaped conduit 42a.

With liquidrising in the left-hand leg of U- shaped conduit 42a, someliquid overflows through oblique conduit 58 into conduit 56, therebyfurther assuring sufilcient liquid being introduced into vaporizer 45aso that the'vapor pressure will build up sufficiently to lift liquidinto receiver 38a.

As the vapor pressure increases above the liquid surface in vessel Ma,the liquid is depressed in this vessel and also in conduit 55. 'At thesame time the columns of liquid rise in the left-hand leg of U-shap'edconduit 42a and conduit 56 until the condenser 35a and conduit 40a arefilled with liquid, and liquid then flows into receiver 38aof evaporator36a.

As the liquid level in vessel Ma falls due to raising of liquid intoreceiver' 38a, less and less liquid. With coil 5| no longer immersed inliquid or only partly immersed in liquid, the coil is no longereffectively cooled by the liquid and less and less condensation ofvapors takes place therein. When condensation of vapors no longer occursin coll 5l the generation of vapors stops in vessel a. due

'to evaporation of liquid therein.

The pressure in the vaporization-condensation circuit is determined bythe temperature of coil 5|. When condensation of vapors does not takeplace in coil 5| due to the rise in temperature of inthe'vaporization-condensation circuit increases sufflciently so that theliquid trap formed by thelower end .of coil 5| and conduit is forcedopen. When this occurs vapor formed in vaporizer 450. can enter theupper part of vessel Mo and further lower the liquid level in thisvessel until it is completely "empty. 6

When the liquid level 'falls in the right-hand leg of U-shaped conduit420. so that it is below the iorizontal part of conduit 56, the liquidlevel will also fall in the left-hand leg of trap 53 to the same extentand vapors can enter the lower end of conduit 56. With suflicientlowering of the liquid level in the right-hand leg of conduit 42a,therefore, the liquid seal at the lower end of conduit 56 is forcedopen. At this time liquid is forced from trap 53 through conduit 52 into'56 will cause lifting .of liquid therein so that liquid is raised inconduit 56 as well as the lefthand leg of U-shaped conduit 42a. Whenthelifting vapor in conduit 56 enters the lower end of conduit 40a at 51,the pressure. is equalized at the upper and lower ends of the liquidcolumn in condenser 35a and U-shaped conduit 42a. With such pressureequalization the. liquid .column in condenser 35a and conduit 42a falls.

- and the liquid returns into accumulation vessel The vapor entering thelower end of conduit 400. through conduit 56 condenses in condenser 35a,and flow of such vapor continues until vaporizer 45a no longer containsliquid. 'Since conduit 56 is filled with vapor no liquid entersvaporizer 45a and the liquidlifting period terminates when vaporizer 45ais exhausted of liquid.

a second accumulation vessel 63.

With liquid now raised into evaporator 36a and the pressure equalized inthe heat transfer system, evaporation of liquid in evaporator 36a isresumed and condensation of this vapor is efi'ected in condenser 35a.The condensed vapor again accumulates in vessel 4 la and a liquidlifting period is again instigated when liquid-overflows through obliqueconduit 58 from conduit 42a into conduit 56.

Fig. 5 diagrammatically illustrates a further modification of theinvention which differs from the preceding embodiments in that vapor inthe heat transfer system is intermittently returned to the higher level,and, after being condensed at such higher level, may flow to one or aplurality of evaporators.

In the modification of Fig. 5 a plurality of evaporators 36b areprovided at a higher level than condenser 35b of the heat transfersystem. Each evaporator 36b is disposed in a separate thermallyinsulated space 31b and includes a receiver 38b and a looped coil 39b.An air-cooled condenser 59 is located above each space 31b and connectedat its lower end by a liquid trap 60 to an upper part of a receiver 38b.

Two of the evaporators 36b are disposed one above the other with theirassociated air-cooled condensers 59 being connected to vertical conduit40b. The other two evaporators 36b are also disposed one above the otherwith their associated condensers 59 being connected to vertical conduit460 which branches off from the lower end of conduit 40b.

As in the previous embodiment, volatile liquid evaporates in evaporators36b and takes up heat thereby producing cold.' The vapors flow fromevaporators 36b through conduits 40b and 400 into condenser 35b in whichthe vapors are cooled and condensed by cooling element I! of the primaryrefrigeration system. The parts of the primary refrigeration systemshown in Fig. 5 and similar to those shown in Fig. 1 are designated bythe same reference numerals.

In Fig. 5 the structure for returning volatile fluid to the evaporators36b at a higher level includes a first accumulation vessel Mb. The lowerend of condenser 35b is connected to the upper part of vessel 4| b by aU-shaped conduit 42b which also includes a second U-shaped liquid trap6!. Within vessel 4lb is disposed a vertical conduit 50b having a coil5Ib at the lower end thereof. The lower end of coil 5| b is connected bya conduit 52b and liquid trap 53b to vaporizer 45b. The upper part ofvaporizer 45b is connected by a conduit 54b to the upper end of verticalconduit 56b.

The lower part of accumulation vessel 4|b is connected by a conduit62'to the upper part of V The lower part of vessel 63 is connected by aconduit 64 to the lower end of a vaporizer 65. Thevaporizer 65 may beheated-in any suitable manner, and, as shown in Fig. 5, is. arranged tobe heated by I heat rejected by absorber I3b.

The absorber 43b may be connected in the primary refrigeration system inthe manner illustrated in Fig. 1 and is diagrammatically shown as alooped coil. The vaporizer 65 is also diagrammatically shown as a loopedcoil extending through absorber.l3b. The absorber l3b is provided withcooling fins 24b for air cooling.

The upper end of vaporizer 65 is connected by a vertical conduit 66 tothe lower end of conduit 40b. This connection at 61. is above the upperend of condenser 35b'of the heat transfer system. The conduit 66 is inheat exchange relation with the left-hand leg of U-shaped conduit 42 h.

The upper part of the'accumulation vessel 63 is connected by a conduit68 to the lower end of conduit 40b and above the condenser 35b. Theupper part of vessel 4 lb is connected by a conduit 55b to conduit 52b.At the point where the lower end of coil 51b is connected to conduit 52bthe latter joins the lower end of conduit 56b. The upper end of conduit56b is connected at 69 to the upper part of vertical conduit 66 andabove the region where it is in heat exchange relation with theleft-hand leg of U-shaped conduit 42b.

When the evaporators 36b are filled with liquid. evaporation of volatilefluid takes place. therein and condensation of the vapors is effected incondenser 35b. The condensate flows from condenser 35b through liquidtrap 6i and U-shaped conduit 421; into the upper part oi? accumulationvessel 4"). When the liquid level in vessel 4|b reaches the upperconnection of conduit 55b, liquid overflows through this conduit andthence through conduit 52b and liquid trap 53b into vaporizer 45b.

The liquid entering vaporizer 45b is vaporized therein and the vaporsflow through conduit 54b into vertical conduit 56b and coil 5"). As inthe modification of Fig. 4, condensation of vapors takes place in theseparts thereby giving up heat to liquid in vessel 4 I b. The condensateflows from coil Bib and returns to vaporizer 45b through conduit 52b andliquid trap 53b. With heating of liquid in vessel 4| b liquid evaporatesand the vapor pressure above the liquid surface builds up. With increasein such vapor pressure liquid is forced downwardly in vessel 4; andupwardly through conduit 62.into the upper part of the secondaccumulation vessel 63 which is located outside the thermally insulatedspace I 8.

Liquid flows from vessel 63 through conduit 64 into vaporizer 65. Invaporizer liquid is vaporized by heat rejected from absorber I 3b of theprimary refrigeration system. The heating effected by absorber l3bresults from the heat liberated with absorption of refrigerant vaporinto absorption liquid in the primary refrigeration duits 40b anld 460into the several condensers 59 in which it is condensed. The condensateflows from the condensers through liquid trap 66 into the receivers 38bof evaporators 36b.

By providing the additional liquid trap 6| in U-shaped conduit42b andarranging the lefthand leg of the latter in heat exchange relation withconduit 66, condenser 35b is filled with liquid during the periods whenvaporized fluid is being returned to the higher level. Due to thermalcontact between conduit 66 and the left-hand leg of U-shaped conduit42b, liquid in the latter is heated and the pressure in this leg becomesapproximately the same as the vapor pressure in vessel b. The pressurein the left-hand leg of U -shaped conduit 42b acts on liquid in theleft- -hand leg of liquid trap 6i and is effective to keep condenser 35bfilled with. condensate or liquid.

By keeping condenser 35b filled with liquid, this condenser is renderedinoperative and condensation of vapors is effected in condensers 59.

During the above described portion of theoperation, the liquid levelfalls in vessel 4Ib due to forcing of-liquid into vessel 63. vAs in themodification of Fig. 4, less and less ofcoil 5lb is immersed in liquidwith lowering of the liquid level,

whereby less and less condensation of vapors takes place in the coil.This results in an increase in the pressure existing in thevaporization-condensation circuit, and, when this pressure increasessufliciently, the liquid trap formed by the lower end of coil Iib,conduit 51b, and conduit lib is forced open. When this occurs vapors incoil lib can flow through conduit lib'into the upper part of vessel lib.With the forcing open of this liquid trap, liquid, rises in conduit 56b.The vapor pressure in vessel lib now becomes suillciently great to forcethe remaining liquid in this vessel through conduit 62 into vessel 63.

With all of the liquid rcmov from vessel lib a path of flow is providedfor the vapors through conduit 02 into accumulation vessel 63. The vaporentering vessel 63 through conduit 62 is conducted through conduit 88into the lower end of conduit llb. When this occurs the liquid incondenser llb falls and flows into vessel lib. This renders condenser35b operative again and vapor flowing upward in conduit 66 is nowcondensed in the condenser. Liquid in conduit 56b flows into vaporizerlib and vaporizes therein. This vapor is condensed in condenser 35b andreturns to accumulation vessel lib.

With vaporizer 65 no longer containing liquid and-vaporizer 45b alsobeing empty, for returning vaporized fluid to the evaporators isterminated, and, since condenser 35b is again operative to condensevapor in the heat transfer system, evaporation of liquid is resumed inevaporators 36b. The pressure in the heat transfer system is nowequalized, the pressure being determined by the low temperature ofcondenser 35b.

In Fig. 6 is diagrammatically illustrated another manner of connecting aplurality of evaporators in a heat transfer system of the charactershown in Fig. andjust described. In place of a number of condensers eachconnected to a separate evaporator, as shown in Fig.. 5, a singlecondenser Sla is employed in Fig. 6. The upper end of condenser 59;; isconnected by a vertical conduit lild to the upper end of the condenserof the heat transfer system, as in the modification of Fig. 5. The lowerend of condenser 59a is connected by a conduit iii to a horizontalconduit ii to which is connected a first group of evaporators lie. Theevaporators 360 are of the flooded type and include a receiver 38c and alooped coil 39c. The lower end of conduit I0 is provided with a liquidtrap 12 which is connected by a vertical conduit 13 to anotherhorizontal conduit ll to which is connected a second group ofevaporators "c. The lower end of conduit 13 is provided with a liquidtrap 15 which is connected by a conduit ll to a horizontal conduit 11having a third group of evaporators llc connected thereto.

A liquid trap 18 at the lower end of conduit 16 is connected by aconduit 19 to a horizontal conduit Bil having a fourth group ofevaporators 360 connected thereto. The upper parts of liquid traps l2,l5, and I8 are connected by conduits ll, l2, and 83, respectively, tovertical conduit lld. 'The lower end of conduit ll is also connected toconduit liid by a conduit ll.

When the condenser of the heat transfer system is filled with liquid andrendered inoperative, vaporous volatile fluid will flow. upwardly inconduit lld, as explained above in connection with the modification ofFig. 5. During this period of the operation of the system, condensationof vapors takes place in condenser 59a.

The condensate formed in condenser 59a flows the period Figs. 2, 3, and

through conduit 10 into horizontal conduit 1i and fills up theevaporators lie at the highest level. When these evaporators are filledwith liquid, liquid overflows from trap 12 into vertical conduit 13whereby the evaporators connected to conduit H are next filled withliquid. In this manner each group of evaporators is filled with liquiduntil liquid flows into the evaporators 36c at the lowest level.

When the condenser of the heat transfer system is no longer filled withliquid and again rendered operative, evaporation of liquid takes placein the evaporators 36c. Thevapors formed in evaporators 36c flow'through conduits ll, 82, 83, and 8l into vertical conduit lid, andthence into the condenser of the heat transfer system. The vapors arecondensed in the condenser and the liquid condensate flows into anaccumulation vessel, as in the modification of Fig. 5, until sufllcientliquid is accumulated whereby volatile fluid is again returned to theevaporators at the higher level.

The heat transfer systems of Figs. 2, 3, and 4 may be provided with aplurality of evaporators connected in series or parallel or in any othersuitable manner. The evaporators may be arranged in the same manner asshown in Fig. 6, for example, with a collection vessel employed in placeof the condenser 59a.

The several groups of evaporators in Fig. 6 may be located in differentfloors of a building. The modifications of Figs, 5 and 6 possess anadvantage overthe systems of Figs. 2, 3, and 4 where volatile fluid isreturned from a lower level through a relatively great height to one ora plurality of evaporators at a higher level. In

4 liquid in the riser conduits returns to the accumulation vessel at theend of a liquid lifting period. Such return flow of liquid is avoided inthe heat transfer systems of Figs. 5 and 6.

While several embodiments of the invention have been shown anddescribed, such variations and modifications are contemplated as fallwithin the true spirit and scope of the invention, as pointed out in thefollowing claims.

What is claimed is: d

l. A method of heat transfer which includes simultaneously vaporizingliquid at a place of evaporation at an upper elevation and condensingvaporized fluid in a place of condensation at a lower elevation,collecting condensate at a place of accumulation, and intermittentlystopping such vaporization of liquid and condensation of fluid andraising liquid condensate to said place of evaporation by trapping vaporabove a surface level of accumulated condensate to exert force thereon,and thereafter releasing such trapped vapor to said place ofcondensation to terminate the raising of liquid condensate to said placeof evaporation.

2. A method of heat transfer which includes vaporizing liquid in a placeof evaporation at an upper elevation, condensing vaporized fluid in aplace of condensation at a lower elevation, collecting condensate in aplace of accumulation, stopping such vaporization of liquid andcondensation of fluid and raising liquid condensate to said place ofevaporation by trapping vapor abovea surface levelof condensate to exertforcecondensation of fluid in said places of evaporation andcondensation, respectively, by releasing such trapped vapor to saidplace of condensation. 3. A method of heat transfer which includessimultaneously vaporizing liquid in a place of evaporation at an upperlevel and condensing vaporized fluid in. a first place of condensationat a lower level, intermittently vaporizing condensate in a place ofvaporization, flowing such vaporized condensate into a second place ofcondensation at a level above the place of vaporization, conductingliquid from the second place of condensation into the placeof-evaporation, and permitting condensation of vaporized condensate inthe second place of condensation by filling the first place ofcondensation with liquid so that vaporized fluid will not be condensedtherein.

4. A method of heat transfer which includes simultaneously vaporizingliquid in a first place of vaporization at an upper elevation andcondensing vaporized fluid in a place of condensation at a lowerelevation, intermittently stopping such vaporization of liquid andcondensationof fluid and raising condensate between said elevations byconducting condensate to a place of accumulation, conductingcondensateto a second place of vaporization when a predeterminedquantity of condensate has accumulated at the place of'accumulation,trapping vapor formed at the second place of vaporization above asurface level of liquid condensate in the place of accumulation to exertforce thereon to raise condensatebetween said elevations, andsubsequently releasing. the trapped vapor to the place of Y condensationto terminate the raising of condensate between said elevations.

5. A method of heat transfer which includes simultaneously vaporizingliquid 'in a place of evaporation at an upper elevation and condensingvaporized fluid in a place of condensation at a lower elevation,conducting liquid from the place of condensation to a place ofaccumulation, intermittently stopping such vaporization of liquid andcondensation of fluid and raising liquid between said elevations andthrough the place of condensation by trapping vapor above a surfacelevel of liquid in the place of accumulation to exert force thereon, andterminating such raising of liquid by releasing trapped vapor to theplace of condensation.

6. A method of heat transfer which includes simultaneouslyvaporizingvolatile liquid in a place of evaporation at an upper elevation andcondensing vaporized fluid in a. place of condensation at, a lowerelevation, conducting liquid condensate from the place of condensationto a place of accumulation, intermittently stopping such vaporization ofliquid and condensation of fluid and raising liquid to the placeofevaporation by trapp ng vapor above a surface level of liquid in theplace of accumulation to exert force thereon and subsequently releasingsuch trapped vapor to said place of condensation to terminate theraising of liquid to the place of evaporation, and heating liquid in theplace of accumulation to form the trapped vapor.

'1'. In the art of heat transfer in which volatile liquid is vaporizedin a place ofevaporation and vaporized fluid is condensed in a place ofcon-' densation, such vaporization of liquid and condensation ofvaporized fluid being effected at substantially the same pressure, theimprovement which consists incollecting liquid condensate in a placeofaccumulation, and returning liquid from the place of accumulation tothe place of evaporation and stopp ng the vaporization of liquid andcondensation of fluid in the places of evaporation and condensation,respectively, by keeping the place of condensation filled with liquid.

8. In the art of heat transfer in which volatile liquid is vaporized ina place of evaporation and vaporized fluid is condensed in a place ofcondensation, the improvement which consists in stopping suchvaporization of liquid and condensation of fluid and returning liquid tothe place of evaporation by collecting liquid condensate in a place ofaccumulation, flowing liquid from the place of accumulation to a placeof vaporization, trapping vapor formed in the place of vaporizationabove a surface level of liquid at the place of accumulation to exertforce thereon to cause fall of liquid level, and subsequently releasingthe trapped vapor from the place of accumulation to stop the return ofliquid to the place of evaporation and to allow liquid condensate tocollect again in the place of accumulation.

9. In the art ofheat transfer in which liquid is vaporized in a place ofevaporation and va-.

porized fluid is condensed in a place of condensation, the improvementwhich consists in re-.

turning liquid to the place of evaporation by collecting liquidcondensate in a place of accumulation, intermittently sip q dom theplace of accumulation to a place of vaporization, v

and trapping vapor formed in the place of vaporization above a surfacelevel of liquid at the place of accumulation to exert force thereon tocause fall of liquid level, and subsequently releasing the trapped vaporfrom said place of accumulation to permit rise of liquid level in thevplace of accumulation.

10. Refrigeration apparatus including'a heat receiving part and acooling element, a heat transfer circuit partly filled with avolatileliquid and including an evaporator in .which. liquid is vaporized and acondenser in which vapors are condensed, said condenser being in heatexchange relation with said cooling element, a vessel con nected toreceive condensate from said condenser,

means associated with said circuit to return con- .densate from saidvessel through said condenser to said evaporator and including a niemberin Q thermal exchange relationwith said heat receiving part, and aheater for heating said part.-

11. A heat transfer system including a circuit partly fllled with avolatile liquid and including an evaporator in which liquid is vaporizedand a first condenser in'which vaporized fluid is condensed, anaccumulator connected to receive liquid from said first condenser, andstructure to return liquid from said accumulator to said evaporatorincluding a vaporizer into which liquid is conducted from saidaccumulator, a second condenser above said evaporator connected toreceive vaporized fluid formed in said vaporizer, said second condenserbeing connected to conduct liquid to said evaporator, and means toprevent liquid from flowing from said first condenser to saidaccumulator while liquid is vaporizing in said vaporizer and vaporizedfluid is condensing in said second condenser.

12. A method of transferring heat which includes vaporizing liquid in aplace of vaporization, flowing to a place of condensation substantiallyall of the vaporized fluid formed in the place of vaporization,condensing the vaporized fluid in the place of condensatiomfiowingcondensate by gravity from said place of condensation to a place ofaccumulation, and vaporizing ,uid, condensate to exert place ofcondensation,

a part of said condensate to cause flow of liquid from the place ofaccumulationthrough the.

place of condensation to the place of vaporiaation.

13. In the art of transferring heat'with the aid of a system having aplace of vaporization in which liquid is vaporized and a place ofcondensation connected to receive substantially all of the vaporizedfluid formed in-the place of vaporization and in which the vaporizedfluid is con-.

densed, the improvement which consists in flowing condensate bygravityfrom the place of condensation to a place of accumulation, andutilizhas accumulated in the place of accumulation,

ing vapor in the system'to cause condensate to flow from the place ofaccumulation through the place of'condensation to the place ofvaporization. a i 14. In a heat transfer systemincluding a circuit forheat transfer fluid having an evaporator at an upper elevation in whichfluid is'vaporized and a condenser at a lower elevation in which isliquefied substantially all of the vaporized fluid formed in theevaporator, a vessel for accumulating liquid below the condenser, aconduit from the lower part of said vessel to the evaporator at theupper elevation, said conduit including the condenser, and means forintermittently trapping vapor above the surface level of liquid in saidvessel to cause alternate upward flow of liquid in said conduit fromsaid vessel and downward flow of condensate said vessel.

15. A method of heat transfer which includes simultaneously vaporizingvolatile liquid in, a

from the condenser into place of evaporation and condensing vaporizedfluid in a place of condensation, flowing liquid condensate from theplace of condensation to a place of accumulation in a path of flow whichalways provides for unrestricted flow of liquid therethrough, andintermittently returning liq- I uid to said place of evaporation byfirst trapping above a surface level of accumulatedliq- I force thereonandsubsequently releasing such trapped vapor to said the trapped vaporbeing vapor trapping vapor .formed in the second, place ,of vaporizationabove a surfacelevel-of liquid condensate at the place-of accumulationto exert .iorce thereon to return, condensate'to the first place ofvaporization, and subsequently releasing the trapped vapor to the placeofcondensation;"

l 18. In a method of transferring heat with the 1 aid of a system inwhich all places are always in unobstructed fluidcommunlcation with eachother andlin which heat is transferred by vaporizing liquid at a, hightemperature plac'e of vaporization, flowing vapor from, such place ofvaporization to a place of condensation where heat is rejected,'andcondensing vapor at the place of condensation, steps of, supplying alimited quantity of liquid to said place of vaporization, forcingcondensate to a"lower temperature place of vaporization upon increase inpressure in said hightemperature place of vaporization resulting fromvaporization of liquid therein, flowing vapor from the lower temperatureplace of vaporization to. the place of condensation afterthehightemperature place of 'vaporizationis depleted of liquid, condensingthe last mentioned vapor and withholding the liquid condensate from boththe high and lower temperature places of vaporization, andagainsupplying a limited quantity of liquid to the high temperature place ofvaporization upon increase in liquid level of the withheld condensate. a

19. A heat transfer system comprising a vaporization condensationcircuit partly filled with avolatile liquid and including low and highertemperature evaporation members and a condensation member, liquidholding means in said circult to withhold liquid condensate from both ofsaid evaporation members and operative to supply a quantity of liquid tosaid higher temperature evaporation member upon rise in liquid level insaid liquid holding means, and said low'tem-' perature evaporationmember being connected to segregated by liquid condensate from saidplace a such trapped vapor by conducting condensate to receive liquidfrom said liquid holding means in a path of flow including saidcondensation member upon increase in pressure in said highertemrperatureevaporation member resulting fro evaporation of liquid therein. 7 20. Avaporization-condensation heat transfer circuit containing a volatilefluid and having two i portions in fluid communication each providedwith a vaporization part, said circuit including a.

, condensation part for condensing therein vaporphase to flowalternately to said portions, said a place of vaporization incommunication with the place of accumulation, and releasing the trappedvapor to the place of condensation after returning liquid to the placeof evaporation, the trapped vapor being segregated by liquid from theplace of condensation, before being released thereto. r

17. A method or heat transfer which includes simultaneously vaporizingvolatile liquid in a flrst place of vaporization'and condensingvaporized fluid in a place of condensation, intermittently returningcondensate to the first place of vapor ization by conducting liquidcondensate from the place of condensation to a placeof accumulation in apath of flow which always provides for unrestricted flow of liquidtherethrough, conducting condensate to a second place of vaporizationized fluid formed in both of said vaporization parts, and structure forcausing fluid in liquid structure being so constructed and r.rrangedthat when liquid flows to one of said portions such liquid passesthrough the condensationpart of said heat'transfer circuit.

21. Ina heat transfer system with a volatile liquid, said circuitincluding a first evaporation member and a condensation member formingafirst portion and a second evaporation member and said condensationmember forming a second portion in fluid communication with said firstportion, said condensation member being capable of condensing thereinvaporized fluid formed in said first, and second vaporizationmembers,and structures embodied in said circuit for causing flow of liquidalternately to said portions, said structure being so constructed andarranged that liquid flowing to one of said portions passes through saidcondensation member.

when a predetermined quantity of condensate comprising avaporization-condensation circuit partly filled 22. A method of heattransfer which includes simultaneously vaporizing volatile liquid in aplace of evaporation arid condensing vaporized fluid in a place ofcondensation, conducting liquid condensate from the place ofcondensation to a place of accumulation, intermittently stopping suchvaporization of liquid and condensation of fluid and returning liquid tothe place of evaporation by trapping vapor above a surface level ofliquid in the place of accumulation to exert force thereon andsubsequently releasing such trapped vapor to said place of condensation,and forming the trapped vapor in the place of accumulation by heatingliquid therein by heat derived from vapors formed in a place ofvaporization to which liquid condensate is conducted.

23. In the art of heat transfer in which volatile liquid is vaporized ina place of evaporation and vaporized fluid is condensed in a place ofcondensation, the improvement which consists in stopping suchvaporization of liquid and condensation of fluid and returning liquid tothe place of evaporation by collecting liquid condensate in a place ofaccumulation, flowing liquid from the place of accumulation to a'placeof vaporization, trapping vapor formed in the place of vaporizationabove the surface level of liquid at the place of accumulation to exertforce thereon to cause fall of liquid level, and stopping the flow ofliquid from the place of accumulation to the place of vaporization afterthe liquid level in the place of accumulation is depressed to apredetermined level by the trapped vapor.

. 24. Refrigeration apparatus including a heat transfer circuit partlyfilled with a volatile liquid and comprising a plurality of partsincluding an evaporator in which liquid is vaporized and a condenserconnected to receive vaporized fluid from said evaporator and disposedbelow the lat ter, and a cooling element in heat exchange relation withsaid condenser to render the latter capable of liquefying vaporizedfluid formed in said evaporator, said circuit being so constructed andarranged that said condenser is intermittently rendered ineffective toliquefy vaporized fluid formed in said evaporator and volatile liquid isintroduced into said evaporator responsive to accumulation of liquid inone of said parts of said circuit. Y 25. A heat transfer systemincluding a circuit partly filled with a volatile liquid and comprisinga plurality of parts including an evaporator in which liquid isvaporized and a condenser connected to said evaporator and in whichnormally is liquefied substantially all of the vaporized fluid formed inthe latter, such vaporization of liquid in said evaporator andcondensation of vaporized fluid in'said condenser being effected atsubstantially the same pressure determined by the temperature of saidcondenser, said circuit being so constructed and arranged that saidcondenser is intermittently rendered ineffective and volatile liquidformed in said condenser is returned to in heat exchange relation withsaid condenser to render the latter capable of liquefying vaporizedfluid formed in said evaporator, said condenser and said accumulatoralways being in un bstructed fluid communication with each other throughsaid connection, and said circuit being so constructed and-arranged thatvolatile liquidis returned intermittently from said accumulator to saidevaporator responsive to accumulation of liquid in said accumuiaton 27.A heat transfer system including a circuit partly filled with a volatileliquid and comprising a plurality of parts including an evaporator inwhich liquid is vaporized and a condenser connected to saidevaporatorand in which'normally is liquefied substantially all of thevaporized fluid formed in the latter, such vaporization of liquid insaid evaporator and condensation of vaporized fluid in said condenserbeing effected at substantially the same pressure determined by thetemperature of said condenser, said circuit being so constructed andarranged that said condenser is intermittently rendered ineffective tocause the pressure in said circuit to increase sufliciently to stopvaporization of volatile liquid in said evaporator responsive toaccumulation of liquid in one of said parts in said circuit, thearrangement and construction of said circuit further being such thatwhen said condenser is rendered ineffective volatile liquid isintroduced into said evaporator.

28. A heat transfer system partly filled with a volatile liquid andcomprising a plurality of parts all of which are in unobstructed fluidcommunication, said parts including a vaporizer in which liquid isvaporized and a condenser connected to said vaporizer and in whichnormally is liquefled substantially all of the vaporized fluid formed inthe latter, the heat resulting from liquefaction of vaporized fluid insaid condenser being rejected to a medium in thermal conductive relationtherewith, said circuit being so constructed and arranged that onlyintermittent flow of fluid from said vaporizer to said condenser is'eflected during operation of the system responsive to accumulation ofliquid in one of said parts of said circuit, and the arrangement andconstruction of said circuit further being such that intermittent flowof fluid from said vaporizer to said condenser is efiected even whensaid vaporizer is partly filled with liquid.

ERIK SIGFRID LYNGER.

